For future reference (cross post from Classifieds):
I've been struggling with [replacing the headset on] my rs6 pro. Just today I stumbled across this Danish site that has the right kind of crazy EC37/30 EC37/34 headset these frames need:
PS: Some of the frames also came with a mix of Chris King EC37 Devolution top and standard EC37 bottom. (I salvaged the top and bottom cups of a CK EC37 headset from a cracked frame, but don't have the crown race or top bearing cover), as seen in this thread:
Note: EC37 is External Cup for 37 mm headtube, i.e. for 1 1/4" forks.